1. Field of the Invention
The present invention relates to a developer and an image forming apparatus using the same. More particularly, the present invention relates to a developer including a toner transfer unit to prevent a toner from leaking when a toner cartridge is attached to and detached from a development cartridge and a color image forming apparatus using the developer.
2. Description of the Related Art
Generally, in image forming apparatuses, a digital image signal corresponding to a desired image is received to form an electrostatic latent image onto a photosensitive medium using an exposure unit such as a laser scanning unit (LSU). Then, the electrostatic latent image is developed into a toner image by using a toner. The toner image is transferred onto a recording medium and the toner image is fused and fixed to the recording medium by applying heat and pressure to the toner image. Consequently, a desired image is formed on the recording medium.
According to the type of toners and carriers used therein, the image forming apparatuses can be classified into dry types and wet types. The dry type image forming apparatuses can be classified into an image forming apparatus including a one-component developer and an image forming apparatus including a two-component developer. The one-component developer forms an image by using only toners. The two-component developer forms an image by using toners and carriers. The toner particles are attached to the carriers.
A single pass type color image forming apparatus generally includes four photosensitive drums, four exposure units for forming electrostatic latent images onto the four photosensitive drums, and four developers for developing the electrostatic latent images formed on the four photosensitive drums by supplying toners of black K, cyan C, magenta M, and yellow Y to the electrostatic latent images, respectively. The four photosensitive drums come into contact with an intermediate transfer belt. Toner images of black K, cyan C, magenta M, and yellow Y are developed on the four photosensitive drums and are superpositionally transferred onto the intermediate transfer belt to form a color toner image. The color toner image is transferred and fixed to a sheet of paper to form a color image.
A built-in type developer includes a container for storing a toner so that the developer refilled with the toner can be used. Alternatively, the developer can be replaced with a split-type developer in which a toner can be supplied from a toner cartridge which is detachable from a development cartridge.
In the built-in type, in order to refill the developer with the toner when the toner is used up, the developer is detached from a main frame. The toner is refilled in the developer and then the developer is attached to the main frame again. Accordingly, there is a relatively small possibility that the toner filled in the developer leaks, which leads to contamination of peripheral devices.
In the split type, in order to refill the developer with the toner again, the toner cartridge for storing the toner is detached from the development cartridge and a new toner cartridge is refilled with toner and attached to the development cartridge. Accordingly, in the way of detaching the toner cartridge from the development cartridge or attaching the new toner cartridge to the development cartridge, the toner remaining in the toner cartridge may leak or a part of the toner filled in the development cartridge may leak out of the development cartridge. This may lead to contamination of the peripheral devices.
Accordingly, there is a need for an improved image forming apparatus to prevent toner from leaking by flattening the toner contained in a development cartridge when a toner cartridge is attached to and detached from the development cartridge.